True story of "the mad queen of Castile" focuses on the innocent daughter of Ferdinand and Isabella contracted into marriage with the infamous Hapsburg heir of the Holy Roman Empire. Juana becomes so enamored of her young libertine husband that her jealously makes her emotionally unstable. Between the faithlessness of her husband and the treachery of her unscrupulous father King Ferdinand she is declared mad and forced into incarceration for most of her life. For a clearer understanding of the events leading to this, read Lawrence Schoonover's intriguing biographical novel "The Prisoner of Tordesillas." How ironic that Juana's younger sister Caterina (Katherine of Aragon) was also betrayed by a ruthless philandering husband (Henry VIII of England) and incarcerated unto death.